Intermediate disk of a cylinder lock

ABSTRACT

AN INTERMEDIATE DISK FOR A CYLINDER LOCK COMPRISING TURNABLE LOCKING DISKS ENCLOSED IN THE CYLINDER OF THE LOCK AND SEPERATED FROM EACH OTHER BY INTERMEDIATE DISKS. THE INTERMEDIATE DISKS HAVE A VENTRAL OPENING FOR THE KEY OF THE LOCK. THE CROSS-SECTION OF THE KEY AND ITS TURNING ANGLE ARE SO CHOSEN, THAT THE CROSS-SECTION OF THE KEY DURING THE OPERATION OF THE LOCK MOVES RELATIVE TO THE INTERMEDIATE DISKS WITHIN A SECTOR SMALLER THAN 360*. IN THE SECTOR OF THE INTERMEDIATE DISKS WHICH IS LEFT UNCOVERED BY THE CORSS-SECTION OF THE KEY THERE IS A RECESS IN THE RIM OF THE DISKS FOR RECEIVING A BAR SHAPED LOCKING MEMBER OF THE LOCK. IN THE SAME SECTOR THE CENTRAL OPENING OF THE INTERMEDIATE DISKS HAS A SMALLER   RADIAL EXTENSION THAN IN THE FIRST MENTIONED SECTOR IN ORDER TO STRENGTHEN THE PORTION BETWEEN THE RECESS AND THE CENTRAL OPENING.

1971 K. H. SOLITANNER 3,623,345

INTERMEDIATE DISK 01' A CYLINDER LOCK Filed March 24, 1969 United StatesPatent U.S. Cl. 70-366 3 Claims ABSTRACT OF THE DISCLOSURE Anintermediate disk for a cylinder lock comprising turnable locking disksenclosed in the cylinder of the lock and separated from each other byintermediate disks. The intermediate disks have a central opening forthe key of the lock. The cross-section of the key and its turning angleare so chosen, that the cross-section of the key during the operation ofthe lock moves relative to the intermediate disks within a sectorsmaller than 360". In the sector of the intermediate disks which is leftuncovered by the cross-section of the key there is a recess in the rimof the disks for receiving a bar shaped locking member of the lock. Inthe same sector the central opening of the intermediate disks has asmaller radial extension than in the first mentioned sector in order tostrengthen the portion between the recess and the central opening.

The invention relates to a cylinder lock comprising a stationarycylinder housing and a rotatable cylinder enclosing a number of lockingdisks turnable by means of the key of the lock, and between the lockingdisks intermediate disks, the turning of which with respect to thecylinder is prevented, and a locking bar locking the cylinder withrespect to the cylinder housing, situated between the outer rim of thelocking disks and the stationary cylinder housing and being movable fromits locking position into a cylinder releasing position in a channelformed by recesses in the rim of the locking disks when aligned in acertain position.

It is important for the reliable function of a lock of the abovementioned type that the set of locking disks is subject to a small axialload and is able to yield somewhat in the same direction. This isusually obtained by making the intermediate disks somewhat yielding inthe axial direction. In the middle of the intermediate disk there is anopening for the key and the weakest portion of the intermediate disk isthe narrow bridge between the recess made to receive the locking bar andthe central opening. This narrow bridge causes difiiculties in thefabrication of the intermediate disk. The punching tool will be weak andthis means that in continuous production the tool has to be renewed moreoften than usual, which in turn raises the production costs of theintermediate disk. If the lock is very small the said narrow bridge willbe so narrow that it can easily break. The object of the invention is tostrengthen this weak portion of the intermediate disk so that smallerlocks than before can be made.

The invention is characterized in that the form of the key of the lockand its turning angle when moving the locking disks from their initialposition to the cylinder releasing position, are in a way known per seso determined that the angle covered by the cross-section of the key issmaller than 360, preferably only 270, the position of the locking barbeing so chosen that it is situated in the sector left uncovered by thecross-section of the key, and that in the intermediate disk its centralkey receiving opening is in the said sector smaller than a full circle.In this way the radial width of the ring shaped intermediate disk willbe larger in the said weak portion, and the outer dimension of the lockcan be made somewhat smaller. In a preferred embodiment of theinvention, the central opening of the intermediate disk has the form ofa segment of a circle, the central angle of the segment being preferablyabout 270.

In the following an embodiment of the invention is described withreference to the attached drawing in which FIG. 1 shows a cross-sectionof a lock according to the invention.

FIG. 2 shows an intermediate disk for a lock according to the invention.

In the drawing 1 indicates a stationary cylinder housing, 2 a turnablecylinder, 3 a locking bar, 4 a locking disk and 5 a key. On the lockingdisk 4 there is a small protrusion 6 which moves approximately in anopening 7 in the cylinder 2 when the key 5 is turned from the initialposition shown in the drawing to the position releasing the cylinder 2.As the cross-section of the key has a semiciricular form, thiscross-section will cover an angle of 270 during the said turningmovement. Hence a right angle sector will remain uncovered and thelocking bar 3 is situated in the middle of this sector. When the lockingdisks 4 have been turned into the cylinder releasing position, therecesses 8 in the locking disks are aligned and form a channel at thelocking bar 3, and the locking bar can move from a groove 9 made in thecylinder housing 1 to the channel formed by the recesses 8 of thelocking disks. When the turning movement of the key is continued, theentire set of locking disks including the intermediate disks turns,bringing with it the cylinder. The turning movement of the cylinderinfluences, for instance, the lock bolt of a door lock or any othermember connected to the cylinder lock in question.

FIG. 2 shows an intermediate disk 10 having in its bottom part aprotrusion 11 extending over a sector of about 90, which protrusion fitsinto the opening 7 of the cylinder and prevents the turning of theintermediate disks relative to the cylinder. The central opening 12 ofthe intermediate disk has the form of a segment of a circle and thecentral angle of the segment is about 270". In the intermediate diskthere is a recess 13 which corresponds to the recesses 8 of the lockingdisks. As the central opening of the intermediate disk is smaller than afull ciricle just at the recess 13, the weak portion 14 will be broaderthan in intermediate disks previously known having a circular centralopening.

The invention is not limited to the embodiment shown, but modificationsof the invention are feasible within the scope of the following claims.

What is claimed is:

1. A cylinder lock comprising a stationary cylinder housing, a rotatablecylinder in said housing, a plurality of locking disks enclosed by saidhousing and turnable by means of a key for the operation of said lock,intermediate disks disposed between said locking disks in a non-turningrelationship with respect to said cylinder, a locking bar locatedbetween the outer surface of said locking disks and said housing, saidintermediate disks being each provided with a recess for receiving saidlock ing bar during the operation of the lock, said intermediate diskshaving a central opening for said key, said key having a cross-sectionand turning through an angle during the operation of the lock sodetermined as to leave a sector of said intermediate disks untraversedby said References Cited cross-section of the key, said recess of eachof the inter- T mediate disks being situated Within said untraversedsec- FOREIGN PATENTS tor, said central opening being non-circular andhaving 25,706 12/1952 i in said untraversed sector a smaller radialextent than in 5 22,581 6/1948 l other parts of said opening. 0 2/ 1952Finland.

2. A lock according to claim 1, in which said central opening of theintermediate disks has the form of a seg- ROBERT WOLFE Primary Examinerment of a ciricle.

3. A lock a ccording to claim 2, in which the central 10 angle of saidsegment is about 270.

